<template>
  <div class="app-container">

    <h2 style="text-align: center;">发布新课程</h2>

    <el-steps :active="1" process-status="wait" align-center style="margin-bottom: 40px;">
      <el-step title="填写课程基本信息"/>
      <el-step title="创建课程大纲"/>
      <el-step title="最终发布"/>
    </el-steps>

    <el-form label-width="120px">

      <el-form-item label="课程标题">
        <el-input v-model="courseInfo.title" placeholder=" 示例：机器学习项目课：从基础到搭建项目视频课程。专业名称注意大小写"/>
      </el-form-item>

      <!-- 所属分类 TODO -->
      <el-form-item label="课程分类">
        <el-select
          v-model="courseInfo.subjectParentId"
          placeholder="一级分类" @change="subjectLevelOneChanged">

          <el-option
            v-for="onesubject in subjectOneList"
            :key="onesubject.id"
            :label="onesubject.title"
            :value="onesubject.id"/>

        </el-select>

        <!-- 二级分类 -->
        <el-select v-model="courseInfo.subjectId" placeholder="二级分类">
          <el-option
            v-for="twosubject in subjectTwoList"
            :key="twosubject.id"
            :label="twosubject.title"
            :value="twosubject.id"/>
        </el-select>
      </el-form-item>


      <!-- 课程讲师 TODO -->
      <!-- 课程讲师 -->
      <el-form-item label="课程讲师">
        <el-select
          v-model="courseInfo.teacherId"
          placeholder="请选择">

          <el-option
            v-for="teacher in teacherList"
            :key="teacher.id"
            :label="teacher.name"
            :value="teacher.id"/>

        </el-select>
      </el-form-item>

      <el-form-item label="总课时">
        <el-input-number :min="0" v-model="courseInfo.lessonNum" controls-position="right" placeholder="请填写课程的总课时数"/>
      </el-form-item>

      <!-- 课程简介 TODO -->
      <el-form-item label="课程简介">
        <tinymce :height="300" v-model="courseInfo.description"/>
      </el-form-item>

      <!-- 课程封面 TODO -->
      <el-form-item label="课程封面">

        <el-upload
          :show-file-list="false"
          :on-success="handleAvatarSuccess"
          :before-upload="beforeAvatarUpload"
          :action="BASE_API+'/oss/upload'"
          class="avatar-uploader">
          <img :src="courseInfo.cover">
        </el-upload>

      </el-form-item>

      <el-form-item label="课程价格">
        <el-input-number :min="0" v-model="courseInfo.price" controls-position="right" placeholder="免费课程请设置为0元"/> 元
      </el-form-item>

      <el-form-item>
        <el-button :disabled="saveBtnDisabled" type="primary" @click="saveOrUpdate">保存并下一步</el-button>
      </el-form-item>
    </el-form>
  </div>
</template>

<script>
  import course from '@/api/course/list'
  import teacher from '@/api/teacher/list'
  import subject from '@/api/subject/list'
  import tinymce from '@/components/Tinymce'
    export default {
      name: "info",
      components:{tinymce},
      data(){
        return{
          saveBtnDisabled:false,
          BASE_API:process.env.BASE_API,//获取dev.env.js的BASE_API的值
          courseInfo:{
            title: '',
            subjectId: '',//二级分类id
            subjectParentId:'',//一级分类id
            teacherId: '',
            lessonNum: 0,
            description: '',
            cover: '/static/01.jpg',
            price: 0
          },
          teacherList:[],
          subjectOneList:[],  //一级分裂
          subjectTwoList:[],   //二级分类
          courseId:'' //当前课程id
        }
      },
      methods:{
        saveOrUpdate(){
          if(this.$route.params && this.$route.params.id){  //是回显
            //更新课程
            course.update(this.courseInfo).then(res=>{
              //获取添加之后的id
              let id = res.data.id
              this.$router.push({path:"/course/chapter/"+id})
            })
          }else { //添加课程
            //添加课程
            course.add(this.courseInfo).then(res=>{
              this.$message({
                type: 'success',
                message: '添加课程信息成功!'
              })
              //获取添加之后的id
              let id = res.data.id
              this.$router.push({path:"/course/chapter/"+id})
            })
          }
        },
        subjectLevelOneChanged(parentId){
          //加载二级分类信息
          subject.findAllTwoSubject(parentId).then(res=>{
            this.subjectTwoList = res.data.twoSubjects
            //清空二级分类
            this.courseInfo.subjectId = ''
          })
        },
        //上传成功调用的方法
        handleAvatarSuccess(res,file){
          this.courseInfo.cover = res.data.url
        },
        //上传之前调用的方法，判断文件类型和大小
        beforeAvatarUpload(file){
          const isJPG = file.type === 'image/jpeg'
          const isLt2M = file.size / 1024 / 1024 < 2

          if (!isJPG) {
            this.$message.error('上传头像图片只能是 JPG 格式!')
          }
          if (!isLt2M) {
            this.$message.error('上传头像图片大小不能超过 2MB!')
          }
          return isJPG && isLt2M
        }
      },
      created() {
        //加载所有讲师
        teacher.findAll().then(res=>{
          this.teacherList = res.data.eduTeachers
        })
        //加载所有的一级分类信息
        subject.findAllOneSubject().then(res=>{
          this.subjectOneList = res.data.oneSubjects
        })
        //判断是回显还是添加
        if(this.$route.params && this.$route.params.id){  //是回显
          //根据id加载courseInfo
          course.getCourseInfo(this.$route.params.id).then(res=>{
            this.courseInfo = res.data.courseInfo
            //根据一级分类id加载二级分类
            subject.findAllTwoSubject(this.courseInfo.subjectParentId).then(res=>{
              this.subjectTwoList = res.data.twoSubjects
            })
          })
        }else { //添加数据

        }
      }
    }
</script>

<style scoped>
  .tinymce-container {
    line-height: 29px;
  }
</style>
